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Caption

Silver mirror test. The silver mirror test is used to distinguish aldehydes from ketones. Tollen's reagent (ammoniacal silver nitrate) and ethanol are added to a solution. If the solution contains aldehydes, the ethanol reduces the silver ions to metallic silver, which deposits on the inside of the reaction vessel (middle). If the solution contains ketones it remains clear (right). The test tube on the left contains water.